Blog

When to Plant Turmeric in Washington County, OR

Washington County, Oregon Zone 8b June

June in Washington County, Oregon — your action list

Your garden in Washington County, Oregon is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 15
Avg. first frost October 27
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.5 hrs
  1. Indoor seed-starting week for turmeric

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Instant PDF download. No spam, unsubscribe any time.

Turmeric is a tropical plant producing bright orange rhizomes with a warm, earthy flavor and potent anti-inflammatory properties. It is closely related to ginger.

Washington County, Oregon is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 27, giving you a growing season of approximately 195 days.

At an elevation of 352 feet, Washington County receives approximately 47.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Turmeric during the growing season.

Washington County, OR (Zone 8b) Moderate season
195 days
Last Spring Frost April 15
195 growing days
First Fall Frost October 27

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Turmeric Planting Risk Windows

Early Start (70% safe) ✓ Fits season (285 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Dec 23 – Jan 6
Recommended (50%) ✓ Fits season (287 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Dec 30 – Jan 13
Safe Start (90%) ✓ Fits season (288 days to spare)
Start indoors: Mar 20 Transplant: May 22 🍅 Harvest: Jan 22 – Feb 5

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Washington County

How your county's soil matches Turmeric's growing requirements.

Soil pH

Your soil pH (5.8–6.4) is within Turmeric's preferred range (5.5–7.5).

Soil Texture

The silt loam soil in Washington County is excellent for Turmeric — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Turmeric will thrive.

How to Plant Turmeric

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Turmeric Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 843 gal / 100 sq ft

Monthly Watering Guide for Turmeric

Turmeric needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Turmeric Needs Rainfall You Supplement Action
Jan 7.4" 0" ❄️ Dormant
Feb 5.7" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 6.5" 3" 3.5" 🚿 Regular watering
May 6.5" 2.8" 3.7" 🚿 Regular watering
Jun 6.5" 1.7" 4.8" 🚿 Regular watering
Jul 6.5" 0.6" 5.9" 🚿 Regular watering
Aug 6.5" 0.9" 5.6" 🚿 Regular watering
Sep 6.5" 1.9" 4.6" 🚿 Regular watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 7.3" 0" ❄️ Dormant
Dec 8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Turmeric Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Turmeric needs ~3,712 GDD — county provides 2,681 GDD May not mature

Turmeric Planting Timeline — Washington County, OR

Turmeric Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest December 30 Dec 30 – Jan 13

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Harvest
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July
August
September
October
November
December Harvest

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

240–300 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

195 days in Washington County

Growing Tips for Turmeric in Washington County

Direct sow Turmeric outdoors after April 15 in Washington County when soil has warmed and frost danger has passed.

Your 195.0-day growing season in Washington County is tight for Turmeric (240.0-300.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant rhizome pieces 2 inches deep in rich, moist soil after last frost. Maintain warmth and humidity. Harvest after foliage dies back in fall. In cold climates, grow in large containers.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turmeric in Washington County, OR?

Washington County is in Zone 8b with an average last frost of April 15. Plan your Turmeric planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, OR?

Washington County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 27.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, OR. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.